Exercise bicycle



FIG. 1 is a rear-right-top perspective view of an exercise bicycle, showing my new design;

FIG. 2 is a front elevational view thereof;

FIG. 3 is a rear elevational view thereof;

FIG. 4 is a right side elevational view thereof;

FIG. 5 is a left side elevational view thereof;

FIG. 6 is a top plan view thereof;

FIG. 7 is a bottom plan view thereof; and,

FIG. 8 is a partially cut-away enlarged view of FIG. 1. 

The ornamental design for an exercise bicycle, as shown and described. 